1. Field of the Invention
This invention relates to an adhesive between metallic substrates or between plastics substrates such as polyvinyl chloride (PVC) or between metallic and plastics substrates and a bonding process using the adhesive.
2. Description of the Related Art
Vinyl chloride-vinyl acetate copolymers have so far been broadly used as an adhesive between metal and metal or between metal and plastic. Among these, vinyl chloride-vinyl acetate-maleic acid terpolymer having carboxyl groups in the molecule has been known to have superior adhesive properties onto metals
Commercially available examples of such resins are Denka Vinyl #1000C, Denka Vinyl #1000CK (both, tradenames of products manufactured by Denki Kagaku Kogyo Kabushiki Kaisha), UCAR.sup.R Solution Vinyl VMCH, UCAR.sup.R Solution Vinyl VMCC (both, registered tradenames of products manufactured by Union Carbide Corp., see U.S. Pat. No. 2,329,456). `S`lec M (tradename of product manufactured by Sekisui Chemical Company. Ltd.) and, Zeon 400X 110A (tradename of product manufactured by Nippon Zeon Co., Ltd.), etc.
Since such copolymers adhere tightly onto metals and have a superior compatibility and affinity with PVC sheet, they are particularly suitable for metal-PVC sheet adhesion and have also been used as a PVC-steel plate adhesive. These instances have been disclosed in various literature and patent publications, as generally described in Yasuo Nonaka, Journal of The Adhesion Society of Japan. 8, 8 (1927); Kikuo Matsuzaka, Journal of The Adhesion Society of Japan, 17, 317 (1981); and Tetsuya Ohhashi. Journal of The Adhesion Society of Japan, 19, 110 (1983).
However, since no insufficient adhesion strength is obtained by way of these copolymers alone, their strength has been supplemented by blending elastomers or various kinds of additives therewith, but an adhesive affording a sufficient adhesion strength has not yet been found.